Author(s): Cheaveau, James ; Nguyen, Hong ; Chow, Barbara ; Marasinghe, Dewdunee ; Mohon, Abu Naser ; Yuan, Hong ; Viana, Giselle Maria Rachid ; Van Schalkwyk, Donelly ; Church, Deirdre ; Chan, Wilson ; Pillai, Dylan R
Date: 2019
Origin: Oasisbr
Subject(s): Mal?ria / diagn?stico; Mal?ria / transmiss?o; Sa?de do Viajante; Rea??o em Cadeia da Polimerase; Testes Sorol?gicos / m?todos; Sensibilidade e Especificidade; Estudos de Casos e Controles
This work was supported by Calgary Laboratory Services.
Calgary Laboratory Services. Clinical Section of Microbiology. Calgary, Alberta, Canada / University of Calgary. Department of Microbiology, Immunology, and Infectious Diseases. Calgary, Alberta, Canada;
Calgary Laboratory Services. Clinical Section of Microbiology. Calgary, Alberta, Canada
Calgary Laboratory Services. Clinical Section of Microbiology. Calgary, Alberta, Canada
McGill University. Department of Epidemiology, Biostatistics, and Occupational Health. Montreal, Quebec, Canada.
University of Calgary. Department of Microbiology, Immunology, and Infectious Diseases. Calgary, Alberta, Canada / Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Laborat?rio de Pesquisas em Mal?ria. Ananindeua, PA, Brasil.
ProvLab Alberta. Edmonton, Alberta, Canada.
Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Laborat?rio de Pesquisas em Mal?ria. Ananindeua, PA, Brasil.
London School of Hygiene & Tropical Medicine. Faculty of Infectious & Tropical Diseases. Department of Immunology & Infection. London, UK.
Calgary Laboratory Services. Clinical Section of Microbiology. Calgary, Alberta, Canada / University of Calgary, Calgary. Department Pathology and Laboratory Medicine. Alberta, Canada / University of Calgary. Department of Medicine. Calgary, Alberta, Canada.
Calgary Laboratory Services. Clinical Section of Microbiology. Calgary, Alberta, Canada / University of Calgary. Department of Medicine. Calgary, Alberta, Canada.
Calgary Laboratory Services. Clinical Section of Microbiology. Calgary, Alberta, Canada / University of Calgary. Department of Microbiology, Immunology, and Infectious Diseases. Calgary, Alberta, Canada / University of Calgary, Calgary. Department Pathology and Laboratory Medicine. Alberta, Canada / University of Calgary. Department of Medicine. Calgary, Alberta, Canada.
The mainstay of malaria diagnosis relies on rapid diagnostic tests (RDTs) and microscopy, both of which lack analytical sensitivity. This leads to repeat testing to rule out malaria. A prospective diagnostic trial of the Meridian illumigene Malaria assay (loop-mediated isothermal amplification [LAMP]) was conducted comparing it with reference microscopy and RDTs (BinaxNOW Malaria) in returning travelers between June 2017 and January 2018. Returning travelers with signs and symptoms of malaria were enrolled in the study. RDTs, microscopy, and LAMP assays were performed simultaneously. A total of 298 patients (50.7% male; mean age, 32.5 years) were enrolled, most visiting friends and relatives (43.3%), presenting with fever (88.9%), not taking prophylaxis (82.9%), and treated as outpatients (84.1%). In the prospective arm (n = 348), LAMP had a sensitivity of 98.1% (95% confidence interval [CI], 90.0%-100%) and a specificity of 97.6% (95% CI, 95.2%-99.1%) vs microscopy. After discrepant resolution with real-time polymerase chain reaction, LAMP had a sensitivity of 100% (95% CI, 93.7%-100%) and a specificity of 100% (95% CI, 98.7%-100%) vs microscopy. After discrepant resolution, RDTs had a sensitivity of 83.3% (95% CI, 58.6%-96.4%) and a specificity of 96.2% (95% CI, 93.2%-98.1%) vs microscopy. When including retrospective specimens (n = 377), LAMP had a sensitivity of 98.8% (95% CI, 93.2%-100%) and a specificity of 97.6% (95% CI, 95.2%-99.1%) vs microscopy, and after discrepant resolution of this set, LAMP had a sensitivity of 100% (95% CI, 95.8%-100%) and a specificity of 100% (95% CI, 98.7%-100%). A cost-benefit analysis of reagents and labor suggests savings of up to USD$13 per specimen using a novel algorithm with LAMP screening.
